Apparatus for photographic contact printing



June 22, 1954 1.. E. VAN DER GRINTEN 2,681,604

APPARATUS FOR PHOTOGRAPHIC CONTACT-PRINTING 5 Sheets-Sheet 1 Filed July19 1950 FIG. l.v

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INYENTOR Louawwx- EVERT VAN DER GRINTEN ATTO N EYS June 1954 L. E. VANDER GRINTEN 2,681,604

APPARATUS FOR PHOTOGRAPHIC CONTACT-PRINTING Filed July 19, 1950 5Sheets-Sheet 2 FIGA.

\NVENTOR LODEWIdK EVERT VAN DER GRINTEN ATTOR N YS June 22, 1954 L. E.VAN DER GRINTEN 2,581,604

APPARATUS FOR PHOTOGRAPHIC CONTACT-PRINTING Filed July 19, 195o 5Sheets-Sheet 3 June 1954 1.. E. VAN DER GRINTEN 2,681,604

APPARATUS FOR PHOTOGRAPHIC CONTACP-PRINTING Filed July 19 1950 5Sheets-Sheet 4 W I5 K FIG] INVENTOR LODEWIJK EVERT VAN DER GRINTEN ATTOR EYS 1.. E. VAN DER GRINTEN 2,681,604

APPARATUS FOR PHOTOGRAPHIC CONTACT-PRINTING June 22, 1954 5 Sheets-Sheet5 Filed July 19 1950 FIGJO.

. INVENTOR LODEWIJK EVERT VAN DERGR\NTE.N

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ATTO 'NEYS Patented June 22, 1954 UNITED STATES PATENT OFFICE APPARATUSFOR PHOTOGRAPHIC CONTACT PRINTING erlands Application July 19, 1950,Serial No. 174,666

Claims priority, application Netherlands July 21, 1949 16 Claims.

The invention relates to a type of photographic contact-printingapparatus comprising a panel of light-transmitting material curved inone direction and substantially straight in the other direction, i. e.linearly curved, having on its convex side, which may be termed astraight convex surface, a flexible applying apron for applying andpressing the material to be exposed onto the panel under tension, thesaid apron extending tangentially off the panel in the resting (i. e. a

feeding or leading) position of the apparatus and following the surfaceof the panel in the working position of the apparatus.

Exposure apparatus as thus far described is known.

A simple form of such apparatus is found in the so-called printingwindows or panels. In such an apparatus the applying apron should betransparent. The operation of such apparatus is, however, not simple andthe apparatus does not function faultlessly.

A more complete form of such a contact printing apparatus effectsexposure from the concave side of the panel. In this latter case thepanel is rotatable about a central axis and the apron is wound andunwound on the panel by this retation.

All these known forms of apparatus have the disadvantage that theoriginal to be copied, after having been applied on the apron togetherwith the copying material in the resting (i. e. feeding) position of theapparatus, has then to be set moving together with the apron. This mayinvolve difficulties especially when the original or the copyingmaterial forms part of a larger aggregate (for example, when it is apage from a book), so that this larger aggregate, properly supported,also has to undergo the whole of this movement. During the movement theoriginal gradually disappears from sight. Thus, if the copy materialshifts or crumples during the movement, this cannot be seen and suchshifting or crumpling cannot be controlled.

It is an object of this invention to provide apparatus in which themovement of the copy material is eliminated or reduced to a minimum.Other important objects of the invention will be apparent from thefollowing description.

According to the present invention photographic contact-printingapparatus, comprises ing the contour of the panel and to sandwichbetween itself and the panel a sheet of light-sensitive material and anoriginal sheet to be copied, means for rolling the panel to and frobetween a resting position in which the panel and the apron are apartand the apron lies tangentially to the panel and a working position inwhich the apron follows the contour of the panel. According to a furtherfeature of the invention, the apparatus comprises means for holding theapron under tension in a direction perpendicular to the generating linesof the panel.

Preferably one end of the apron is attached to the panel, or to thecasing holding the panel, along a generating line of the panel and theother end terminates at an edge which is thin and flat and is parallelto the generating lines of the panel. Preferably the said terminal edgeis anchored in a fixed position within the apparatus.

The invention will now be described with reference to the accompanyingdrawings which illustrate preferred forms of the apparatus of theinvention.

Figs. 1 and 2 illustrate, in the resting and working positionsrespectively, an apparatus for ing copies on a table.

Figs. 3 and 4 similarly illustrate a simple apparatus for copying pagesfrom books.

Figs. 5 and 6 illustrate, again in the resting and working positionsrespectively, an apparatus with a stationary source of light and devicesfor screening the light in the resting position.

Figs. '2 and 8 illustrate, in the resting and working positionsrespectively, an apparatus with a cylindrical panel capable of rollingto and fro.

Figs. 9 and 10 illustrate, in the resting and working positionsrespectively, apparatus in which a source of light moves together withthe panel and is screened in the resting position.

Referring to Figs. 1 and 2, the apparatus comprises a lamp i, areflector casing 2, a curved panel 3, an applying apron 4, a table 5 onwhich the free end of the apron is fastened at 55, the other end of thesaid apron being fastened at T to the panel or to the exposure casing.Two flexible, elastic, tightened straining tapes 8, provided on eitherside of the apron, are secured to the panel or casing at 2?, pass alongat the outside of the curved panel 3 or the corresponding part of theexposure casing 2 towards the back of the table 5 where they are securedat 28. These flexible elastic, tightened straining members 3 thus crossthe apron l and run onto and off the curved panel 3 in the reversedirection to the apron itself. This device keeps the apron underconstant tension, on the one hand via table and on the other hand viathe panel system. The apparatus, as illustrated in all the figures, isoperated from the left.

A device for limiting the final position with respect to the rollingmovements of the panel comprises the link HS, which is pivotally mountedon the table 5 at I? and which has a slot in which the pin it mounted onthe casing 2 ited in its freedom of movement. The weight E3: illustratesdiagrammatically that the centre of gravity of the panel together withall the parts joining in its movement is so disposed that it is stableonly in the feeding position l) or the working position (Fig. 2) whilebeing unstable in the intermediate positions.

In the resting (i. e. loading or feeding) position according to Fig. 1,material for contact printing may be placed onto the apron and when thepanel and the exposure casing are transferred by means of the handle 8from the position of Fig. 1 to that of Fig. 2 and kept in the latterposition, all the conditions required for contact-printing arefulfilled.

From the above description it is clear that apparatus according to theinvention may be very simply constructed and very easily operated.

In a particularly satisfactory form of the invention the free end of theapron forms a terminal edge engaged by tension members, said edge beingparallel to the generating lines of the panel, being flat and thin, orat least thinning towards the end, and extending freely, unobstructed bythe tension members acting upon the said edge. Such an apparatus isillustrated in Fig. 3.

Referring to Fig. 3, the apparatus comprises a source or" li ht l, areflector casing 2a, a curved panel Be, an apron 4a and a table Theapron is fastened to the panel or casing at la. A plate ii? lies belowthe apron 4a and is connected at one and to the terminal edge 6 or" theapron. The flexible, but non-elastic straining tapes d, provided oneither side of the apron, are secured at 2'? to the panel or casing andpass along the outside of the curved panel Ea or the corresponding partof the casing 2a towards the edge of the plate ll! opposite the edge ofthe said plate connected to the terminal edge They engage the said edgepassing over the two pulleys provided on the supports and connect withthe springs 35, which are anchored to supports 32. The straining members8a thus cross the apron la and run onto and off the curved panel 3a inthe reverse direction to the apron itself. The apron la is thus keptunder tension via the plate 16 and on the other hand via the panelsystem, in a manner analogous to that of Fi s.

i and 2. The exposure asing has a handle while the plate is is supportedby the supports i I and connected to table 5a. The supports leave thebottom surface of the plate iii substantially free. Near the fasteningthe apron and the plate l form a fiat thin edge.

The spring pulls, by means of tapes 8a passing the roller the edge 27 inFig. 3 to the right and somewhat in a downward direction. The forceexerted therefore is substantially di-- rested to the right and istransmitted through the curved panel to the edge la where it acts (videFig. 3) in a horizontal direction and to the right. At the edge la theforce just referred to is transmitted to the applying apron 4a with theresult that this apron is also pulled to the right, which means thatthere is a tension in the apron pulling the edge 6 also to the right. Atthis place 3 however the plate 18 engages the apron 4a and prevents thisedge from being moved to the right. The plate [2- therefore of coursehas to exert a reaction force to the left.

The apparatus of Fig. 3 is suitable for making copies, for example,reflex copies, from pages of books. The way in which the apparatus isused for this purpose is illustrated in Fig. 3. As there shown the pagel2 of the book to be copied is laid over the apron 4a, while thephotosensitive material 13 on which a reflex copy of this page is to beproduced is laid over the page 12. The apparatus is rolled from theresting position to the working position in the same way as described inrelation to Figs. 1 and 2, thus reach ing the working position of Fig.4. The latter figure also illustrates that the apron 4a and the curvedpanel 3a are interconnected in such relative position that in theworking position (in which the apron is wound onto the panel) a freeedge M of the panel extending on one of the generating lines of thepanel registers with the terminal edge 6 of the apron, i. c. it meetsthe said terminal edge 5 as accurately as possible when the workingposition is reached. As is demonstrated by the book illustrateddiagrc... matically in Fig. 4, this disposition presents especialadvantages, if it is desired to photoprint the page right up to the foldor spine of the book.

In Fig. 4 the page l2 and the photo-sensitive material 13 have, ofcourse, become invisible, because the apron 4a is pressed onto thecurved panel 3a.

In the apparatus of Figures 1-4 the source of light moves with the panelassembly during the passage from the resting position to the worl ingposition and vice versa. Figs. 5 and 6 illustrate diagrammatically thatthis is, of course, not necessarily the case and that the source oflight may, for example, also be stationary. certain circumstances thisis advantageous since the provision of a simple screen 26 attached tothe panel prevents any undesirable light from the source of light frompassing through the curved panel to the apron in the resting position(Fig. 5), while in the case of lamps sensitive to shock it isadvantageous if they are not moved.

The Still plate 25, illustrated in Figs. 3-6, which is substantiallyparallel to the surface of the freely extending end. or" the apron, outwhich may also have a slight curvature (for example, with the convexside turned upwards) provided its generating lines are parallel to thoseof the curved panel, and which. ends with one of its edges in the flatand thin terminal edge of the apron, constitutes a particularly enicienttension device for a flat, thin and free terminal edge.

In the apparatus of this invention the pressure (copying pressure)required for good contact is produced, in a manner known per se, by thetension of the apron in cooperation with the convex side of the panel.With a given tension this copying pressure increases the curvature ofthe panel increases, in other words as its radius decreases. In Figs. 7'8 an apparatus is illustrated in the resting position and workingposition respectively, in which the curved panel is a complete cylinderSo having a small radius. This apparatus operates in essentially thesame way as the apparatus according to Figs. 1 and 2. The tension devicein these two figures is as follows: at '10 the apron 4c is extended bycans of the two flexible and elastic straining tapes 80. These tapes areprovided on either side beyond the width of the apron 4c and are loopedabout the curved panel together with this apron, as is clearly visiblein Fi 7, the apron passing between the two straining members. Theelastic tapes 8c are fastened to the table 50 and at 280.

When the apparatus according to the invention is combined with a sourceof light fastened to the concave side of the curved panel, in such amanner that this source of light moves with the panel, the peculiarfeatures of the apparatus according to the invention may be simplyturned to account as illustrated in Figs. 9 and 10 in order to screenthe light in the feeding position.

In the embodiment of Figs. 9 and 10, the source of light Id is partiallysurrounded by a screen 2 i, which may act as a reflector at the sametime. It is rotatable in the casing 211, and during rotation the sourceof light id remains in the centre. The screen 2i carries a lever $22disposed. outside the casing, having a pivot point 2-? with which therod 24 engages. The rod 2d pivots about a fixed point 25 on table M.

In the working position (Fig. 10) the opening of the screen 2! isdirected towards the curved panel. During the movement from thewo.....ing position to the resting position (Fig. 9) the rod 24 keepsthe screen 2! in substantially the same direction via the lever 22, orat least substantially the same direction is attained again when theresting position has been completely reached. In the resting positionthe rays of the source of light cannot reach the panel 3. When themovement is reversed the screen ill will return to the position shown inFig. 10 and its opening will again be directed towards the panel What Iclaim is:

1. In a contact photcprinting apparatus, the combination of a supportproviding an elongated trackway for a rolling exposure member, anexposure member comprising a cylindrically curved light-pervious paneldefining only part of a cylinder and reliable bodily on said traclrwayto move said surface to and fro along a path tangential to said surfacewith a r cking motion relative to the support, said trackway extendingalong path, a flexible apron held to said panel surface and extendingalong it and tangentially from it to a terminal portion, and meansanchoring said terminal portion to said support so as to preventrelative movement thereof longitudinally of the apron, so that rollingthe panel away from said terminal portion exposes part of the apron toreeive original and light-sensitive sheets for exposure and so thatsheets placed over the exposed apron may be brought into close contactwith. the panel by rolling it over them toward said terminal portion.

2. An apparatus as described in claim 1, the apron being attached to theexposure member near and across an end of the panel surface remote fromsaid terminal portion.

3. In a contact photoprinting apparatus, the combination of a supportproviding an elongated trackway for a rolling exposure member, an exposure member comp-rising an arcuate light-por vious panel having anouter surface convex in one direction and straight in the transversedirection, said exposure member being supported and roclrable bodily onsaid trackway to move said surface to and fro relative to the support ina path tangential to said surface, said traclrway extending along saidpath, a flexible held to said panel surface and extending along it a dtangentially from it to a terminal portion, d means anchoring saidterminal portion to said support so as to prevent relative movementthereof longitudinally of the apron, so that rocking the panel away fromsaid terminal portion exposes part of the apron to receive original andlight-sensitive sheets for exposure and so that sheets placed over theexposed apron may be brought into close contact with the panel byrocking it over them toward said terminal pertion, said terminal portionof the apron having a terminal edge substantially parallel to generatinglines of said panel surface, and said panel surface having at one end afree edge substantially coinciding with said terminal edge when thepanel rocked fully toward the latter.

4. In a contact photoprinting apparatus, the combination of a supportpresenting a substantially fiat working surface, an exposure membertiereover comprising a curved light=-pervious having an outer surfaceconvex in one direction and straight in the transverse direction, saidexposure member being supported by said panel surface bearing upon saidworking surface and being rollable bodily to and fro over the latter ina path tangential to said panel surface, a flexible apron held to saidpanel surface and extending along it and tangentially from it over theworking surface to a terminal portion, and means anchoring said terminalportion to said support so to prevent relative movement thereoflongitudinally of the apron, so that rolling the pa cl away from saidterminal portion spreads the apron over the working surface to receiveoriginal and light sensitive sheets for exposure and so that sheetsplaced over the spread apron may be brought into close contact with thepanel by rolling it over them toward said terminal portion.

5. In a contact photoprinting apparatus, the combination of a supportpresenting a substan tially fiat working surface, an exposure memberthereover comprising a curved light-pervious panel having an outersurface convex in one diection and straight in the transverse direction,said exposure member being supported by said panel surface bearing uponsaid working surface and being rollable bodily to and fro over thelatter in a path tangential to said panel surface, a flexible apron heldto said panel surface and extending along it and tangentially fro. overthe working surface to a terminal portion, and means anchoring saidterminal portion said support so as to prevent relative movement thereoflongitudinally of the apron, so but rolling the panel away from saidterminal portion spreads the apron over the working cur ae to receiveoriginal. and light sensitive posure and so that sheets placed overaoron may be brought into close contact w panel by rollin it over themtoward ter minal portion, said support having a thin, freely protrudingend portion forming an e parallel to generating lines of said panelsurface, and said terminal portion of the apron extending over saidedge.

6. In a contact photoprinting apparatus, the combination of a supportpresenting a substantially fiat working surface, exposure ineinberthereon comprising a cylindricaily cur ed light pervious panel definingless than half a cylinder, said panel being supported on its convexsurface by said working surface and reel-r able bodily over the latterbetween a feeding p tion in. which its backward end approaches d workingsurface and an exposing position in which its forward end approachesworking surface, a flexible apron held to the backward end of the paneland extending along and tanthe so" gentially from its convex surfaceover said working surface to a terminal portion, means anchoring saidterminal portion to said support so to prevent relative movement thereofs 1-; of the apron, and tensioning means i flexible tensioning memberscomprising elastic bands.

8. An apparatus as described in claim e tensioning members comprisingsubst inelastic bands and tensioning sori' mounted on the support.

In a contact photo-printing app; combination of an exposure membercon-prising a light-pervious panel of which the outer surface 1 convexin one direction and straight in the ransre se direction, a supportproviding a xtending along a path tange to ace, said exposure member olable bodily to and fro on said traclsw 0 oil said surface along a tang:

surface, a flexible apron held to W Jer and arranged to extend over saidsu ace .;an entially from it to a terminal portion of the c saidterminal portion being anchored to a part of said support so as toprevent Eli said terminal portion longitudin? pron, the rolling of saidmember away from said ctrminal portion uncovering said apron so that eetmaterial may be placed on the apron I r extending along a pathtangential to sa d ace, said exposure member being supper ed androllable bodily to and fro on said traclzway so as to roll said surfacealong a path tangential surface, a flexible apron held to s and arrangedto extend over c lgentially from it to a terminal portion of t apron,said terminal portion being anc'nc terminal portion longitudine therolling of said member ,d terminal portion uncovering said e osure, andsheet material so pla rapped against said surface by the rolling ofember toward said terminal portion, there a thin stiif transverse edgeat the end of terminal portion, and means holding said ie substantiallyparallel to generating of no surface and in a position where it rotrudesunobstructed so as to be inserted into t book when said member is rolledas said terminal portion.

In a contact photo-printing apparatus,

*: convex in one direction and straight to said surface, a flexibleapron held to said member and arranged to extend over said surface andtangentially from it to a terminal portion oi the apron, said terminalportion being anchored to a a part of said support so as to preventmovement of said terminal portion longitudinall3' of the apron, therolling of said member away from said terminal portion uncovering saidapron so that sheet material may be placed on the apron for exposure,and sheet material so placed being wrapped against said surface by therolling of said member toward said terminal portion, and means forapplying to said panel a tension acting in a direction opposite to thedirection of extension of the apron from said panel surface so as tokeep the apron in a stretched condition.

12. In a contact photo-printing apparatus, the combination of anexposure member comprising a light-pervious panel of which the outersurface is convex in one direction and straight in the transversedirection, a support providing a trackway extending along a path tang.-l2.i to said surface, said exposure member here ported and rollablebodily to and fro on said trac way so as to roll said surface along ortangential to said surface, a flexible apron to said member and arrangedto extend o surface and tangentially from it to a terminal portion ofthe apron, said terminal portion bein anchored to a part of said supportso as p event movement of said terminal portion tudinally of the apron,the rolling of said 1r ber away from said terminal portion unco" saidapron so that sheet material may be pl on the apron for exposure, andsheet :xaterial so placed being wrapped against surface by the rollingof said member toward said terir portion, and means for applying to saidpanel a tension acting in a direction opposite to the direction ofextension of the apron from p urface so as to keep the apron in a scondition, said tension applying means in 11;,

extending tangentially from said surface opposite direction to a part ofsaid supp mote from said terminal portion, said members crossing theapron near the location where the apron leaves said surface.

13. An apparatus as described in claim 12, said apron and said flexiblemembers having interconnected end portions and forming a continuous bandlooped about said panel.

14. In a contact photo-printing apparatus, the combination of anexposure member comprising, a light-pervious panel of which the outer srface convex in one direction and straiglr- 1D. the transversedirection, a support providing a trackextending along a path tangentialto said surface, said exposure member being supported rollable bodily toand fro on said trackway so as to roll said surface along a pathtangential to said surface, a flexible apron held to said member andarranged to extend over said surface and tangentially from it to aterminal portion of the apron, said terminal portion being anchored to apart of said support so as to prevent movement of said terminal portionlongitudinally of the apron, the rolling of said member away from saidterminal portion uncovering said apron so that sheet material may beplaced on the apron for exposure, and sheet material so placed beingwrapped against said surface by the rolling of said member toward saidterminal pol tion, and means lying in the path of movement of abutmentmeans on said exposure member to limit the rolling movement of the panelin each di rection of such rolling movement.

15. In a contact photo-printing apparatus, the combination of anexposure member comprising a light-pervious panel of which the outersurface is convex in one direction and straight in the transversedirection, a support providing a trackway extending along a pathtangential to said surface, said exposure member being supported androllable bodily to and fro on said trackway so as to roll said surfacealong a path tangential to said surface, a flexible apron held to saidmember and arranged to extend over said surface and tangentially from itto a terminal portion of the apron, said terminal portion being anchoredto a part of said support so as to prevent movement of said terminalportion longitudinally of the apron, the rolling of said member awayfrom said terminal portion uncovering said apron so that sheet materialmay be placed on the apron for exposure, and sheet material so placedbeing wrapped against said surface by the rolling of said member towardsaid terminal portion, a light source at the concave side of said panel,a light shield movable to and from a position blocking the path of lightemission from said source to said panel, and means responsive to therolling movement of said exposure member for moving said shield to andfrom said light blocking position, respectively, as said member isrolled away from and toward said terminal portion.

16. In a contact photo-printing apparatus, the combination of anexposure member comprising a light-pervious panel of which the outersurface is convex in one direction and straight in the transversedirection, a support providing a trackway extending along a pathtangential to said surface, said exposure member being supported androllable bodily to and fro on said trackway so as to roll said surfacealong a path tangential .10 to said surface, a flexible apron held. tosaid member and arranged to extend over said surface and tangentiallyfrom it to a terminal portion of the apron, said terminal portion beinganchored to a part of said support so as to prevent movement of saidterminal portion longitudinally of the apron, the rolling of said memberaway from said terminal portion to a feeding position uncovering saidapron so that sheet material may be placed on the apron for exposure,and sheet material so placed being wrapped against said surface by therolling of said member toward said terminal portion to a workingposition, a light source at the concave side of said panel, a tubularlight shield rotatably mounted in said exposure member and partiallysurrounding the light source, said shield having an opening for thepassage of light and having a reflective inner surface, and means forrotating said shield about said source so as to block the path of lightbetween said source and said panel when said exposure member is infeeding position and to dispose said opening therebetween when said memher is in working position.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,222,961 Szasz Nov. 26, 1940 2,223,341 Ernst Dec. 3, 19402,290,478 Matlas July 21, 1942 2,335,742 Creange Nov. 30, 1943 2,383,785Foster Aug. 28, 1945 2,492,476 Harvey Dec. 27, 1949 2,512,437 De Lacy WJune 20, 1956 2,514,892 Miller July 11, 1950 FOREIGN PATENTS NumberCountry Date 231,30 Germany Feb. 20, 1911 253,732 Germany Nov. 14, 191262,224 Netherlands Dec. 15, 1948

